Zafgen's obesity drug drives dramatic weight loss in PhII test

CHICAGO--Zafgen has revealed some impressive weight-loss data from a midstage study of its experimental therapy beloranib, highlighting interim results after 12 weeks of treatment in 19 obese white women.

In that relatively small and homogeneous group, there were signs of significant drops in weight without changes in diet and exercise for those on the drug. Cambridge, MA-based Zafgen, which plans to present the data on Sunday at the annual American Diabetes Association (ADA) meeting, reported that the treatment provided up to 10 kilograms, or 22 pounds, of weight loss. The company expects to report full data from the 148-patient study later this summer.

Obesity is a top cause of Type 2 diabetes and a hot topic at the ADA meeting. While Zafgen is initially focused on developing injected beloranib for people who are obese, many overweight diabetics could eventually benefit from the treatment as an alternative to bariatric surgery, Xconomy reported. Though tested in far fewer patients to date than recently approved obesity drugs from Vivus ($VVUS) and Arena ($ARNA), Zafgen's experimental therapy has shown more dramatic drops in weight so far.

Beloranib, which Zafgen licensed from CKD Pharma in Korea, works differently from any approved weight-loss drugs. While many other diet drugs tell the brain that the patient is full, beloranib targets an enzyme called MetAP2 that governs output and use of fatty acid molecules. By blocking the enzyme, the company, a 2009 Fierce 15 winner, says, the body produces less fatty acid molecules and stored fats are burned for energy.

Here are some of the highlights from the 19-patient data set:

  • Patients on the 0.6-mg, 1.2-mg and 2.4-mg doses of the therapy dropped an average of 3.8 kilograms, 6.1 kilograms and 9.9 kilograms respectively, while the 5 patients on placebo gained an average of 1.8 kilograms. (A kilogram equals about 2.2 pounds.) So Zafgen is touting the dose-dependent effects of the treatment.
  • The most frequent side effects included sleep problems, nausea and vomiting. Two of the patients on the highest studied dose of the drug dropped out of the trial. Yet the company said that none of the side effects qualified as serious or severe, and nobody died.
  • Some other benefits of treatment included reductions in LDL or bad cholesterol, triglycerides and inflammation-related C-reactive protein.

I plan to meet with venture-backed Zafgen executives on Sunday morning, so check back here for updates. Until then…

- here's the release
- see Bloomberg's article
- and Xconomy's report

Special Report: Zafgen - 2009 Fierce 15